1. Technical Field
The present invention relates to a telephone switching system, a telephone switching method, a telephone switching program, a telephone switchboard, and a management terminal. In particular, the present invention relates to a telephone switching system, a telephone switching method, a telephone switching program, a telephone switchboard, and a management terminal for preventing illegal use (or dishonest use).
2. Background Art
Recently, cases in which a malicious third party illegally accesses a telephone switchboard of a company through the Internet and makes an international telephone call or the like through that telephone switchboard by using means for disguising his/her call as being a call from an extension telephone of the company or means for changing the setting of the telephone switchboard, and then the company is charged a large amount of telephone charges later are occurring one after another. To cope with such a problem, development of techniques related to networks and telephone systems capable of recognizing illegal use have been underway.
For example, Japanese Unexamined Patent Application Publication No. H06-350698 discloses an invention in which at least one attribute of a telephone call in which a network is accessed is monitored in real time and when this attribute indicates abnormal illegal use of the network, a customer of the network is notified of the abnormal illegal use in real time.
Further, Japanese Unexamined Patent Application Publication No. H07-023460 discloses a method for making use of a blacklist in a mobile telephone system. Specifically, Japanese Unexamined Patent Application Publication No. H07-023460 discloses the following invention. Each mobile telephone exchange as well as each base station is equipped with a blacklist for visitor stations. Further, when each mobile telephone exchange receives an outgoing call or a location registration request transmitted from a roaming mobile device through a base station, it searches the blacklist of visitor stations for a device number of that mobile device. Then, when the device number is found in the blacklist, each mobile telephone exchange disconnects its connection. Further, when the device number is not found in the blacklist and the mobile device is determined to be a non-subscriber mobile device, each mobile telephone exchange records the device number in the blacklist of visitor stations.